Rotor comprising pivoted hammer provided with armored outer portion and plate-shielded inner portion



Aug. 4, 1953 w. c. ROGERS 2,647,695 ROTOR COMPRISING PIVOTED HAMMER PROVIDED WITH ARMORED OUTER PORTION AND PLATE-SHIELDED INNER PORTION Filed Nov. 1, 1950 26 22 l INVENTIOYR" WAYNE 6. ROGERS 2/ 2 I Fig.5 BY

ATTORNEY Patented Aug. 4, 1953 ROTOR "COMPRISING PIVOTED HAMMER PROVIDED WITH 'ARMORED OUTER POR- TION AND PLATE-SHIELDED INNER POR- TION Wayne C.- Rogers, Worcester, Mass., assignor to Riley Stoker Corporation,

Worcester, Mass., a

corporation of Massachusetts Application November 1, 1950, Serial No. 193,431

This invention relates to hammer mills, and more particularly to apparatus of the type having a rotor with a series of hammers secured'to'its periphery, these hammers being arranged to strike pieces of material (for example coalland thereby crush the same.

With such mills as heretofore constructed the hammers have been subjected to very severe conditions. The material being crushed often causes these parts to wear away rapidly by the eifect of impact and abrasion. Any hard foreign bodies, such as pieces of tramp metal which may be mingled with the material, produce shocks and often result in breakage of the hammers. Attempts to solve these problems 'by selection of a suitable material for the hammers have not been particularly successful. In general, materials tough enough to withstand heavy shocks wear away too rapidly from the abrasive as materials hard enough to withstand abrasion are too brittle and will be broken when tramp metal enters the machine. I g

It is accordingly one object of the invention to provide a comparatively simple an inexpensive hammer mill capable of operation for very long periods of service without the need for repair.

It is a further object of the invention to provide an improved construction for the revoluble hammers of a hammer mill, whereby these parts will be capable of withstanding heavy. shocks without breaking, and severe abrasive conditions without appreciable Wear.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of partsset forth in the specification and covered by the claims appended hereto.

In accordance with the invention there is provided a rotor with a series of .hammers'secured to its periphery. The rotor may be in the form of a disk, and each hammer comprises an outer portion or head having a flat front surface and an inner supporting portion fastened to' the disk. A protective armor of extremely hard material is secured to the front surface of the head, and a separate shield is mounted in front of the supporting portion. The supporting portion of each hammer preferably includes two laterally spaced apertured ears, and each shield preferably comprises a plate having two laterally spaced apertured ears extending rearwardly therefrom. A single pin or the like preferably extends through the ears of each hammer and the ears of the corresponding shield to provide a pivotal connection between these parts and the rotor disk action, wherea '5 Glaims. (Cl. 241-197) Referring to the drawings illustrating one embodiment of the invention, and in which like reference numerals indicate like parts,

Fig. 1 is a vertical section through a hammer mill, the section being taken on the line I--l of Fig. 2;

Fig. 2 is a section taken on thel ine 2-2 of Fig. 1;

Fig. 3 is a fragmentary side elevation of a rotor and associated parts;

Fig. 4 is a front elevation of a hammer;

Fig. 5 is a side elevation of a hammer;

Fig. 6 is a side elevation of a shield; and

Fig. 7 is a rear elevation of a shield.

The embodiment illustrated in Fig. 1 comprises a housing l0; having an upper entrance opening II for the coarse material, a lower discharge opening l2 for the crushed material, and a collecting pocket M for tramp metal or other noncrushable material. A horizontal rotatable shaft l5 extends through the housing, and on this shaft there is mounted a vertical rotor disk IS with a series of hammers l8 secured to its periphery. An arcuate grid or screen I9 is mounted within the housing I ll beneath the rotor disk and spaced slightly from the outer ends of the hammers. As shown inFig. 2, there are preferably two of the disks I 6, axially spaced from one another and each carrying a separate series of hammers.

Referring particularly to Figs. 4 and 5, each hammer l8 comprises a generally rectangular outer portion or head 2| having a fiat front surface 22, and an inner supporting portion 23 including two laterally spaced apertured ears 24, these parts preferably being made of a strong tough material such as steel. The front surface 22 is protected by suitable armor plate 26. This armor plate comprises eight fiat rectangular pieces of an extremely hard material, preferably tungsten carbide, although other hard materials can be employed. The armor plate may be secured to the surface 22 by silver soldering or brazing. As shown in Fig. 2, the spaced ears 24 straddle the peripheral portions of the rotor disks [6 at assembly, and each pair of laterally adjacent hammers is pivotally attached to the disks by a pin 2'! which extends through the ears and the disks. Preferably the disks are provided with outwardly projecting circumferentially spaced 1apertured lugs 28 through which the pins 21 exend.

A separate device is associated with each hammer [8 to protect the inner supporting portion 23 thereof from abrasion and wear. For this purpose a flat rectangular plate or shield 29 is mounted in front of the portion 23, the plate having two laterally spaced apertured cars 30 extending rearwardly therefrom. These parts are preferably formed of manganese steel or a similar tough hard material capable of resisting abrasion.v The ears 39 are spaced apart somewhat farther than the hammer ears 24 so that they may straddle the hammer ears at assembly, as shown in Fig. 2, and the pin 21 may extend through both sets of ears. In order tohold the pin 21 in place, a sleeve 32 is mounted on the central por--- tion. of the pin between the adjacent ears 30, and a cotter pin 33 extends diametrically through this sleeve and the pin 21. The outer edge of the shield plate 29 slightly overlaps the armorzplate 25.

The operation of the invention will now be apparent from the above disclosure. Coarse material will be fed through the opening I 1 into the housing 10, and this material will be struck by the revolving hammers l8 and thereby crushed sufficiently to pass downwardly through the grid I9 and the discharge passage 12. A y large pieces of tramp metal or other uncrushable material will be thrown into the. pocket I l in known manner. The armor plate 26 will protect the heads 2| of the hammers from abrasion, while the heads will provide the weight, strength and toughness required to support thearmor plate properly and ensure the desired crushing action. While practically all of the crushing will be brought about by the engagement of the armored heads 2| with the material, there will nevertheless be an appreciable cloud of dust located inwardly of these heads. The shields will protect the inner supporting portions 23 of the hammers from the abrasive action of this dust cloud. Thus the hammers l8. will have an ex.- tremely long life of useful service. In ordinary operation, centrifugal force will hold the ham! mom. and shields in the substantially radial positions shown in Fig. 3, but if a. large heavy piece oftrampmetal should enter the machine these parts are free to swing rearwardly about the pins 21 and into the spaces between the lugs 28, as indicated by the broken lines.

- Having thus described my invention, what I claim as new and desire tosecure by Letters Patent. is:

1. A hammer mill comprising a rotor disk, at

series, of hammers spaced around the periphery of the disk, eachhammer including an outer portion or head having a fiat-front surface and an inner supporting portion having two laterally spaced apertured ears which straddle the adja-. cent portion of the disk, a protectivearmor of extremely hard material secured to they front surface of each hammer head, a separate shield plate located in front of the inner portion of each hammer to protect the samefrom abrasion, two laterally spaced apertured ears on each shield plate and straddling the adjacent. portion of the disk, and a pin or the like extending throughthe hammer ears, thev shield plate ears, and the disk.

.two laterally spaced apertured cars which straddle the adjacent lug, a protective armor of extremely hard material secured to the front surface of each hammer head, a separate shield plate located in front of the inner portion of each hammer to protect the same from abrasion, two laterally spaced apertured ears extending rcarwardly from. each shield plate and straddling the adjacent lug, and a pin or the like extending through each lug, the adjacent hammer ears, and the adjacent shield plate ears.

3.. A. hammer mill as set forth in claim 2 in which the shield plate ears are spaced farther apart than the hammer ears so as to straddle the same.

4, A hammer mill comprising a rotor, a series of hammers spaced around the periphery of the disk, each hammer being pivotally mounted on the rotor, each hammer including an outer portion having an impact surface and an inner portion by which it is mounted on the rotor, a protective armor of extremely hard material secured to the impact surface of each hammer, a separate. shield plate mounted in front of the inner portion of eachhammer to protect the same from abrasion, each said shield plate being mounted on a common pivotal axis with its respective hammer 5. A hammer mill comprising a rotor, a hammer, a shield plate, said hammer being pivotally mounted on the rotor, said hammer having an outer portion having an impact surface and an inner portion by which it is mounted on the rotor, and a. protective armor of extremely hard material secured to the impact surface of said hammer, said shield plate being pivotally mounted on: said rotor immediately adjacent the hammer and-being situated in front of the inner portion of the, hammer to protect the same from abrasion, the hammer and the shield plate being mounted on a common pivotal axis.

WAYNE C. ROGERS.

References Cited in the file of this patent UNITED STATES PATENTS 

